The aim of this project is to evaluate the capabilities of 2-dimensional (2D) and 3-dimensional (3D) endoluminal ultrasound leading to its use to diagnose and stage a variety of tumors. This research plan comprises three elements: 1) 2D and 3D endoluminal ultrasound performance studies using phantoms; 2) evaluation of 3D ultrasound imaging using an animal tumor model and validation of a variety of 3D reconstructional models; 3) clinical 2D and 3D Validation in human tumors. The project will focus on three tumors: uroepithelial, endometrial and esophageal. The candidate, Dr. Ji-Bin Liu, has particular interest in evaluation of tumors in a variety of areas of the body using such animal models as rabbit VX2 tumors and woodchuck hepatomas. His expertise in animal experimentation has evolved over the four years since he joined the Division of Diagnostic Ultrasound. The candidate has had extensive experience working with miniature transducers in a variety of animal models and patients over the past four years. The candidate will take courses in computer science, biostatistics, physics and engineering to extend his knowledge base. The candidate's sponsor, Barry B. Goldberg, M.D., Director of the Division of Diagnostic Ultrasound and the Jefferson Ultrasound Research and Education Institute, has had more than thirty years of experience in ultrasound and has been an investigator on many grants. The candidate's other mentors include an ultrasound physicist, a computer scientist and a biostatistician. There is significant research material and space available. This includes an ultrasound physics laboratory, an animal facility with ultrasound and x-ray equipment and a computer center with existing 3D reconstruction programs.